Timberland Bancorp (NASDAQ: TSBK) appoints Aprio as new auditor post merger

Rhea-AI Filing Summary

Timberland Bancorp, Inc. reported a change in its independent registered public accounting firm following a merger of its prior auditor. On January 1, 2026, Delap LLP, the Company’s former auditor, merged with Aprio, LLP, and Delap resigned as auditor. The Audit Committee approved Aprio, LLP as the successor independent registered public accounting firm.

Delap’s audit reports on Timberland Bancorp’s consolidated financial statements for the fiscal years ended September 30, 2025 and 2024, and for each of the years in the three-year period ended September 30, 2025, as well as on internal control over financial reporting as of September 30, 2025, contained no adverse opinions, disclaimers, or qualifications. The Company states there were no disagreements with Delap and no reportable events during those periods. Timberland Bancorp also notes it did not consult with Aprio on accounting matters or audit opinions before this appointment and has filed a letter from Delap to the SEC as an exhibit.

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SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): January 1, 2026

Timberland Bancorp, Inc.

(Exact name of registrant as specified in its charter)

Washington	0-23333	91-1863696
State or other jurisdiction Of incorporation	Commission File Number	(I.R.S. Employer Identification No.)

624 Simpson Avenue, Hoquiam, Washington	98550
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number (including area code) (360) 533-4747

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions.

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, par value $.01 per share		TSBK		The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. [ ]

Item 4.01 Changes in Registrant’s Certifying Accountant

On January 1, 2026, Timberland Bancorp, Inc. (the “Company”) was notified that Delap LLP (“Delap”), the Company's independent registered public accounting firm, merged with Aprio, LLP effective on January 1, 2026. The combined audit practices operate as Aprio, LLP (“Aprio”). In connection with the notification of the merger, Delap has resigned as the auditors of the Company and the Audit Committee of the Company’s Board of Directors approved the appointment of Aprio, as the successor to Delap, as the Company’s independent registered public accounting firm.

The audit reports of Delap on the Company’s consolidated financial statements for the fiscal years ended September 30, 2025 and 2024, and for each of the years in the three-year period ended September 30, 2025, and internal control over financial reporting as of September 30, 2025, did not contain an adverse opinion or a disclaimer of opinion, nor were they qualified or modified as to uncertainty, audit scope or accounting principles.

During the fiscal years ended September 30, 2025 and 2024, and the subsequent interim period through January 1, 2026, there were no (a) disagreements with Delap on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure, which, if not resolved to Delap’s satisfaction, would have caused it to make reference to the subject matter of the disagreement in connection with its reports on the Company’s financial statements, or (b) reportable events requiring disclosure pursuant to Item 304(a)(1)(v) of Regulation S-K.

During the years ended September 30, 2025 and 2024, and the subsequent interim period through the date of this Current Report on Form 8-K, neither the Company, nor anyone on its behalf, consulted with Aprio regarding: (i) either the application of accounting principles to a specified transaction, either completed or proposed, or the type of audit opinion that might be rendered on the Company’s financial statements; or (ii) any matter that was either the subject of a “disagreement,” as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions to that item, or a “reportable event,” as described in Item 304(a)(1)(v) of Regulation S-K.

The Company provided Delap with a copy of this Current Report on Form 8-K prior to its filing with the Securities and Exchange Commission (the “Commission”) and requested that Delap furnish the Company with a letter addressed to the Commission stating whether it agrees with the above statements and, if it does not agree, the respects in which it does not agree. A copy of Delap’s letter to the Commission, dated January 7, 2026, is filed as Exhibit 16.1 to this Form 8-K and is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d)          Exhibits

16.1        Letter from Delap LLP, dated January 7, 2026

104         Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.

	TIMBERLAND BANCORP, INC.
DATE:  January 7, 2026	By:  /s/ Marci A. Basich
	Marci A. Basich         Chief Financial Officer

FAQ

What auditor change did Timberland Bancorp (TSBK) disclose?

Timberland Bancorp disclosed that Delap LLP, its independent registered public accounting firm, merged with Aprio, LLP effective January 1, 2026. Following this merger, Delap resigned as the Company’s auditor, and the Audit Committee approved Aprio, LLP as the new independent registered public accounting firm.

Were there any issues with Delap LLP’s prior audit opinions for Timberland Bancorp (TSBK)?

The Company states that Delap’s audit reports on Timberland Bancorp’s consolidated financial statements for the fiscal years ended September 30, 2025 and 2024, and for each of the years in the three-year period ended September 30, 2025, as well as on internal control over financial reporting as of September 30, 2025, did not contain adverse opinions, disclaimers of opinion, or qualifications as to uncertainty, audit scope, or accounting principles.

Did Timberland Bancorp (TSBK) report any disagreements with Delap LLP?

No. Timberland Bancorp reports that during the fiscal years ended September 30, 2025 and 2024, and the subsequent interim period through January 1, 2026, there were no disagreements with Delap on accounting principles, financial statement disclosure, or auditing scope or procedures, and no reportable events under Item 304(a)(1)(v) of Regulation S-K.

Did Timberland Bancorp (TSBK) consult with Aprio, LLP before appointing it as auditor?

The Company states that during the years ended September 30, 2025 and 2024, and the subsequent interim period through the date of the report, neither Timberland Bancorp nor anyone on its behalf consulted with Aprio on the application of accounting principles, the type of audit opinion that might be issued, or on any matters involving disagreements or reportable events.

What correspondence from Delap LLP did Timberland Bancorp (TSBK) file with the SEC?

Timberland Bancorp provided Delap with a copy of the report and requested a letter addressed to the SEC stating whether Delap agreed with the Company’s disclosures. A letter from Delap LLP to the SEC dated January 7, 2026 is filed as Exhibit 16.1 and incorporated by reference.

Which stock exchange lists Timberland Bancorp (TSBK) common stock?

Timberland Bancorp’s common stock, par value $0.01 per share, is listed on The Nasdaq Stock Market LLC under the trading symbol TSBK.